PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART B 7 The Nervous System

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc  Reflex—rapid, predictable, and involuntary response to a stimulus  Occurs over pathways called reflex arcs  Reflex arc—direct route from a sensory neuron, to an interneuron, to an effector

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Effector Sensory neuron Motor neuron Integration center (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 1 Stimulus at distal end of neuron Skin Receptor (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 2 Stimulus at distal end of neuron Skin Receptor Sensory neuron (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 3 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Sensory neuron Integration center (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 4 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Sensory neuron Motor neuron Integration center (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 5 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Effector Sensory neuron Motor neuron Integration center (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b–c Spinal cord Sensory (afferent) neuron Inter- neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (quadriceps muscle of thigh) Effector (biceps brachii muscle) Synapse in ventral horn gray matter (c) (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 1 Spinal cord Sensory receptors (stretch receptors in the quadriceps muscle) (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 2 Spinal cord Sensory (afferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 3 Spinal cord Sensory (afferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Synapse in ventral horn gray matter (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 4 Spinal cord Sensory (afferent) neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Synapse in ventral horn gray matter (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 5 Spinal cord Sensory (afferent) neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Effector (quadriceps muscle of thigh) Synapse in ventral horn gray matter (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 1 Spinal cord Sensory receptors (pain receptors in the skin) (c)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 2 Spinal cord Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 3 Spinal cord Inter- neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 4a Spinal cord Inter- neuron Motor (efferent) neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 4b Spinal cord Inter- neuron Motor (efferent) neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (biceps brachii muscle) (c)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b–c Spinal cord Sensory (afferent) neuron Inter- neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (quadriceps muscle of thigh) Effector (biceps brachii muscle) Synapse in ventral horn gray matter (c) (b)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Somatic reflexes  Activation of skeletal muscles  Example : When you move your hand away from a hot stove

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Autonomic reflexes  Smooth muscle regulation  Heart and blood pressure regulation  Regulation of glands  Digestive system regulation

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Patellar, or knee-jerk, reflex is an example of a two-neuron reflex arc Figure 7.11d

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS)  CNS develops from the embryonic neural tube  The neural tube becomes the brain and spinal cord  The opening of the neural tube becomes the ventricles  Four chambers within the brain  Filled with cerebrospinal fluid

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS) Figure 7.12a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain  Cerebral hemispheres (cerebrum)  Diencephalon  Brain stem  Cerebellum

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.12b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebral Hemispheres (Cerebrum)  Paired (left and right) superior parts of the brain  Includes more than half of the brain mass  The surface is made of ridges (gyri) and grooves (sulci)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Lobes of the cerebrum  Fissures (deep grooves) divide the cerebrum into lobes  Central fissures: between frontal and parietal  Surface lobes of the cerebrum  Frontal lobe  Parietal lobe  Occipital lobe  Temporal lobe

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Specialized areas of the cerebrum  Primary somatic sensory area  Receives impulses from the body’s sensory receptors  Located in parietal lobe; surface of postcentral gyrus  Primary motor area  Sends impulses to skeletal muscles  Located in frontal lobe ; it is the surface of precentral gyrus  Broca’s area  Involved in our ability to speak

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13c

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.14

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebral areas involved in special senses  Gustatory area (taste) frontal lobe  Visual area: visual cortex of occipital  Auditory area: auditory cortex of temporal lobe  Olfactory area: olfactory cortex of temporal lobe

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Interpretation areas of the cerebrum  Speech/language region  Language comprehension region  General interpretation area

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Association Area  Interpret incoming data or coordinate a motor response  Somatic sensory association area: recognize light touch  Somatic motor association area: (pre motor cortex): coordinate learned movements.

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebral Processing Center  Control complex motor activities and analytical functions.  Lateralized: either involved with L or R hemisphere.  Wernicke’s area: receives information form all sensory association. Plays a role in your personality / coordinates memory. Left Hemisphere  Prefronal cortex: frontal lobe –predicts future consequences-anxiety and tension

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hemispheres  Left: dominant: mathematical / logical decision making/ speech/ language skills/.  Premotor cortex is larger on left side in right handed individual  Right: sensory and relates body to sensory environment. Recognize faces.  Left handed individuals: high percent musicians/artists.  Corpus callosum link 2 hemispheres together.

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Memory  Fact memory: What is your name?  Skill memory: How do you throw a ball? With repetition skill memories get incorporated into unconscious.  Short term : does not last long  Long term: goes through memory conversion. Stored in cerebral cortex.

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13c

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Layers of the cerebrum  Gray matter—outer layer in the cerebral cortex composed mostly of neuron cell bodies  White matter—fiber tracts deep to the gray matter  Corpus callosum connects hemispheres  Basal nuclei—islands of gray matter buried within the white matter-function in the subconscious control, provide general pattern and rthymn.

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Limbic System:  Includes: olfactory cortex/ several basal nuclei/ gyri/tracts between cerebrum and diencephalon.  Emotional states and related behavioral drives  Links conscious intellectual functions of cerebral cortex with autonomic function of brainstem.  Long term memory storage.  Amygdaloid bodies link the limbic system, cerebrum and various sensory systems. Link emotion with memory.  Hippocampus: learning an long term memory. Damage in alzheimers.

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.15

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Sits on top of the brain stem  Enclosed by the cerebral hemispheres  Made of three parts  Thalamus  Hypothalamus  Epithalamus

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.12b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Thalamus  Surrounds the third ventricle  The relay station for sensory impulses  Transfers impulses to the correct part of the cortex for localization and interpretation

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Hypothalamus  Under the thalamus  Important autonomic nervous system center  Helps regulate body temperature  Controls water balance  Regulates metabolism

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Hypothalamus (continued)  An important part of the limbic system (emotions)  The pituitary gland is attached to the hypothalamus

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Epithalamus  Forms the roof of the third ventricle  Houses the pineal body (an endocrine gland)  Includes the choroid plexus—forms cerebrospinal fluid

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Attaches to the spinal cord  Parts of the brain stem  Midbrain  Pons  Medulla oblongata

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem Figure 7.16a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Midbrain  Mostly composed of tracts of nerve fibers  Has two bulging fiber tracts— cerebral peduncles  Has four rounded protrusions— corpora quadrigemina  Reflex centers for vision and hearing

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Pons  The bulging center part of the brain stem  Mostly composed of fiber tracts  Includes nuclei involved in the control of breathing

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Medulla Oblongata  The lowest part of the brain stem  Merges into the spinal cord  Includes important fiber tracts  Contains important control centers  Heart rate control  Blood pressure regulation  Breathing  Swallowing  Vomiting

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Reticular Formation  Diffuse mass of gray matter along the brain stem  Involved in motor control of visceral organs  Reticular activating system (RAS) plays a role in awake/sleep cycles and consciousness

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Reticular Formation of the Brain Stem Figure 7.16b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebellum  Two hemispheres with convoluted surfaces  Provides involuntary coordination of body movements

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebellum Figure 7.16a